When hydrogen is added to a combustion fuel in a compression ignition engine, a reduction in the brake specific fuel consumption and emissions can be achieved. This reduction can be achieved because hydrogen ignites and burns rapidly, helping to vaporize and mix the combustion fuel with the oxygen, resulting in a faster combustion reaction. The addition of hydrogen can have further profound effects in engines utilizing oxygen restriction techniques. For example, when a lower concentration of nitrogen oxides is desired, the hydrogen can counteract the ignition delay caused by a lack of oxygen. This reduction in an ignition delay can result in the engine achieving a peak cylinder pressure earlier in the power-stroke, for example, of a 4-cycle engine, which can allow for an increased expansion time, and ultimately in more work per each combustion event. The use of liquid hydrogen or gaseous hydrogen in such an engine is not practical from a safety standpoint. Furthermore, liquid hydrogen must be refrigerated which, is itself an energy intensive process and gaseous hydrogen is expensive, it lacks an established infrastructure, and appropriate storage equipment is expensive and not easily procured.
An improved method of providing hydrogen that can be used in a combustion engine and a method of controlling its addition to the engine is therefore desired.